FMS flight management systems are well known. They make it possible to formulate the flight plan of an aircraft on each mission, by taking account of parameters specific to the aircraft and to the flight conditions such as the payload, the weight of the aircraft, the quantity of fuel on board, the temperature, the wind as well as time constraints imposed by the ATC air traffic control bodies: required departure and/or arrival time slot.
The flight plan describes notably the set of points (“waypoints”) or positions above which the aircraft must pass, with notably the corresponding altitude and speed at each point. It provides a vertical flight profile for the various phases of the aircraft, typically the climb phase CLB, the cruising phase CRZ and the descent phase DES.
Several types of flight plan are considered by FMS systems. The pilot usually has at his disposal an active flight plan, a temporary flight plan and one or more secondary flight plan(s).
The active flight plan is the flight plan currently undergoing processing and the latter controls the aircraft's automatic pilot.
The temporary flight plan is a copy of the active flight plan to which modifications are made by the pilot, such as for example the addition or modification of points or turning points. This flight plan can thereafter become the active flight plan when the pilot so decides.
The secondary flight plan is a stored flight plan that may be selected as active flight plan by decision of the pilot.
In the current realizations, the information relating to these various flight plans is displayed in the aircraft flight deck by using two screens. A first screen, usually called the navigation screen, and designated by the acronym ND standing for the expression “Navigation Display”, makes it possible to graphically display the active, temporary, and/or secondary flight plans, projected horizontally on the terrestrial surface. A second screen, called the control and display unit, or simply the control unit and usually designated by the acronym CDU standing for the expression “Control Display Unit”, serves as interface for displaying each flight plan, comprising notably the list of points of the flight plan with their predictions of time, altitude, speed, fuel and wind and with the parameters between the points (name of route or procedure, distance, angle of route, etc.). The pilot can, with the aid of this interface, make modifications to each of the flight plans.
To verify the content of a flight plan, the crew need to view the trajectory graphically with the aid of a display by using, for example, the navigation screen ND. Moreover, a textual display usually taking the form of a textual list of the segments and points of a flight plan makes it possible to take cognizance of the details so as notably to validate the said plan. This textual display is implemented, for example, with the aid of the control unit.
Navigation and control screens have a limited display capability on account of their size. Textual display of the list of points is very useful since the verification of a flight plan based solely on the trajectory displayed graphically on the navigation screen ND is insufficient. Indeed, there are not enough information elements related to the points on the graphical display, such as, for example, speed predictions. There are also not enough information elements displayed related to the segments. Moreover, the graphical display of the trajectory on the navigation screen can only be done over a maximum display radius, usually of the order of 320 Nm. This maximum radius is also designated by the word “range”. With this display scale, it is difficult to effect global and accurate verification of the trajectory associated with the flight plan.
In order to verify the flight plan in detail, the pilot has the control unit at his disposal. The latter also having limited display capabilities related to its size, the pilot is afforded the possibility, in the current systems, of scrolling the list of points of the flight plan so as to be able to access the entire content of the said flight plan. The displacement by scrolling of the flight plan portion displayed has formed notably the subject of the patent entitled Methods and apparatus for integrating, organizing, and accessing flight planning and other data on multifunction cockpit displays (U.S. Pat. No. 6,542,796).
Usually, the pilot is afforded the possibility of browsing through the textual display of a flight plan page by page with the aid of scrolling keys symbolized by up and down arrows, or else with the aid of a pointing ball, also called a “trackball”.
The existing schemes making it possible to move around in the list of displayed points and segments of a flight plan do not allow fast access to a chosen portion of the said plan. Indeed, in the current systems, the pilot must scroll this list continuously for arrival at the portion in which he is interested.